JPWO2012095959A1 - Inverted pendulum type moving body - Google Patents

Abstract

A pair of wheels that are suspended on a moving body body and have a floor surface as a traveling surface, and are provided on the same plane perpendicular to the traveling direction, a driving mechanism that rotates the wheels, and a mobile robot that controls the driving mechanism In an inverted pendulum type moving body having a drive control unit for maintaining the inverted state of the main body, a wheel rotational speed measuring unit for measuring the rotational speed of the wheel, and a front and rear of the main body for measuring a tilt angular velocity in the front-rear direction of the mobile body A direction angular velocity measurement unit, a suspension actuator for moving the wheel in the up and down direction, and a suspension actuator drive unit for driving the suspension actuator are measured. When changing to, drive the suspension actuator on the wheel side that has changed beyond the set value , Inverted pendulum type moving body, characterized in that to change the vertical position of the wheel.

Description

  The present invention relates to an inverted pendulum type moving body provided with a travel stabilization device.

  As a prior art regarding stepping over a step when an inverted pendulum type moving body (so-called a self-supporting mobile robot) moves on a road surface with a step, various traveling operations such as Patent Document 1 and Patent Document 2 have been proposed. .

  For example, in the inverted pendulum type moving body described in Patent Literature 1, an example in which wheel driving control is performed by inversion control in a state where a wheel is brought into contact with a step and the center of gravity of the moving body is moved forward to give torque over the step. Is described.

  In addition, the inverted pendulum type moving body described in Patent Document 2 describes an example in which an obstacle sensor is provided, and the moving body is lifted by releasing the compression of the spring immediately before the step to get over the step.

JP 2009-55682 A JP 2009-35157 A

However, in the above-described conventional technique, there is a question as to whether or not an inverted pendulum type moving body that is small and has a high moving speed can perform a certain step-up operation.
In addition, in an inverted pendulum type moving body that is small and has a high moving speed, it is necessary to detect a smaller step because the influence from the external environment becomes large. However, in general, a high-precision sensor has a drawback of a large volume.

  In addition, the wheel drive torque is reduced for downsizing, and there is also a problem that a margin of torque that can be used for maintaining the posture of the inverted pendulum when stepping over a step is reduced.

  For example, in the technique described in Patent Document 1, the position of the step is obtained from an optical sensor or a deviation of the wheel rotation angle. In this case, the optical sensor generally has a tradeoff between the step detection accuracy and the detection distance, and a small step cannot be detected unless it is a short distance. Therefore, there is a problem that when the step is detected, the operation is not in time or the step itself cannot be detected. Further, when the wheel rotation angle is used, a deviation occurs in the wheel rotation angle even on an inclined surface, so that there is a possibility of erroneous detection.

  In the technique described in Patent Document 2, energy stored in an elastic body is used to lift the moving body at a stroke when the moving body reaches a step. For this reason, it is difficult to cope with the height of the step, and in some cases, the wheel may be dragged by the moving body, and the wheel may fly and idle.

  The object of the present invention is an inverted pendulum type equipped with a traveling stabilization device that realizes stable traveling by reliably detecting the step when the inverted pendulum type moving body gets over the step and reducing the torque required for stepping over the step. It is to provide a moving body.

  An object of the present invention is to provide an inverted body comprising a pair of wheels suspended on a mobile body, a drive mechanism for rotating the wheels, and a drive control unit for controlling the drive mechanism to maintain the mobile robot body in an inverted state. In a pendulum type moving body, a wheel rotational speed measuring unit that measures the rotational speed of the wheel, a main body longitudinal angular velocity measuring unit that measures a tilt angular velocity in the front-rear direction of the movable body, and a movement of the wheel in the vertical direction A suspension actuator drive unit that drives the suspension actuator, and the body longitudinal angular velocity measured by the body longitudinal angular velocity measurement unit and the left or right speed of the pair of wheels are equal to or greater than a set value. The suspension actuator on the wheel side that has changed beyond the set value is driven. It is accomplished by varying the wheel up and down Te.

  Further, the object is to provide a main body front-rear direction angle measuring unit that measures a tilt angular velocity in the front-rear direction of the mobile body main body, and a main body front-rear direction angle measured by the main body front-rear direction angle measuring unit and a left or right of a pair of wheels More preferably, when the speed of the wheel changes to a set value or more, the suspension actuator on the wheel side that has changed to a set value or more is driven to change the vertical position of the wheel.

  The object is more preferably provided with a wheel drive mechanism that adds a drive torque to the wheel on the side whose wheel position has been moved upward in accordance with the amount of movement of the wheel.

  It is more preferable that the suspension actuator is driven so that the vertical positions of the pair of wheels are equal when the longitudinal inclination angle velocity or the longitudinal inclination angle of the movable body is equal to or less than a set value.

  According to the present invention, when an inverted pendulum type moving body climbs over a step, the inverted pendulum type is provided with a traveling stabilization device that realizes stable traveling by reliably detecting the step and reducing the torque required for stepping over the step. A moving body can be provided.

It is a schematic block diagram of the conventional inverted pendulum type moving body. It is a schematic block diagram of the moving body concerning one Example of this invention. 1 is a system configuration diagram of a moving body according to an embodiment of the present invention. It is a flowchart explaining the process of the driving | running | working stabilization apparatus concerning one Example of this invention.

Now, the conventional structure of the inverted pendulum type moving body targeted by the present invention will be described with reference to the inverted pendulum type moving body shown in FIG.
FIG. 1 is a schematic configuration diagram of a conventional inverted pendulum type moving body.
In FIG. 1, an inverted pendulum moving body 1 includes a moving mechanism 2 inside a moving body main body (housing) 10. The moving mechanism 2 is controlled by a movement control unit 3 and a crossing assistance operation generating unit 4. The inverted pendulum moving body 1 is provided with a gyro 11 inside the moving body main body 10 as means for obtaining a tilt angle in the front-rear direction and the left-right direction of the moving body main body 10.

  The moving mechanism 2 includes an actuator 14, a driving wheel 13, and a wheel motor 12 on the left and right sides of the lower part of the inverted pendulum moving body 1. Drive wheels 13 provided on the left and right sides of the inverted pendulum moving body 1 are connected to the moving body main body 10 via actuators 14 respectively. The actuator 14 corrects the posture according to the inclination of the mobile body 10. The drive wheel 13 is driven by a wheel motor 12. The gyro 11 is connected to the movement control unit 3 and the crossing assistance operation generation unit 4 by electric signals.

  Although the conventional inverted pendulum moving body 1 includes the actuator 14 as described above, the actuator 14 does not cope with the inclination of the inverted pendulum moving body 1 due to a step, and cannot overcome a high step. .

Therefore, the inventors of the present invention detect the height of the step from the angle deviation between the tilt angle of the inverted pendulum moving body 1 that travels while tilting and the tilt angle of the inverted pendulum moving body 1 when contacting the step, Considering raising the drive wheel 13 according to the height of the step.
As a result of the examination, the following examples were obtained.

An embodiment of the present invention will be described below with reference to FIG.
FIG. 2 is a schematic structural view of an inverted pendulum type moving body provided with an embodiment of the present invention, and FIG. 2 (a) is a side view thereof. FIG. 2 (b) is a front view thereof.
In FIG. 2, the inverted pendulum moving body 1 includes a moving mechanism 2 inside a moving body main body (housing) 10. The moving mechanism 2 is controlled by a movement control unit 3 and a crossing assistance operation generating unit 4. The inverted pendulum moving body 1 includes a gyro 11 inside the moving body main body 10 as means for obtaining an inclination angle in the front-rear and left-right directions of the moving body main body 10.

  The moving mechanism 2 includes an actuator 14, a driving wheel 13, and a wheel motor 12 on the left and right sides of the lower part of the inverted pendulum moving body 1. The driving wheels 13 provided on the left and right sides of the inverted pendulum moving body 1 are connected to the moving body main body 10 via the actuators 14, respectively, and the distance from the moving body main body 10 is changed when the actuator 14 operates. Can do. The drive wheel 13 is driven by a wheel motor 12.

  The gyro 11 is connected to the movement control unit 3 and the crossing assistance operation generation unit 4 by electric signals. The gyro 11 measures the front-rear direction inclination angle θ and the front-rear direction inclination angular velocity dθ with respect to the vertical plane of the mobile body 10 shown in FIG.

  The XYZ coordinate axes described in each of FIGS. 2A and 2B are coordinate axes provided for ease of explanation, and are coordinate axes for the mobile body 10. The + Y direction is referred to as the front, the -Y direction as the rear, the + X direction as the right, the -X direction as the left, and the + Z direction as the upper. The inverted pendulum moving body 1 is movable in the front-rear direction. FIG. 2B shows a state in which either the left or right side of the wheel 13 rides on the step A portion.

Next, the system configuration will be described with reference to FIG.
FIG. 3 is a system configuration diagram of a moving body according to an embodiment of the present invention.
In FIG. 3, the gyro 11 and the overriding assist operation generation unit 4, the movement control unit 3 connected to the wheel control unit 5, and the overriding assist operation generation unit 4 connected to the gyro 11, wheel control unit 5, and actuator control unit 6. Is configured as a calculator. The movement control unit 3 includes a movement command unit 7 and an inversion control unit 8 which are implemented by software.

  The wheel control unit 5 adds the inverted torque τi acquired from the movement control unit 3 and the torque τc given from the crossover assisting operation generation unit, and controls the wheel motor 12 to output the added torque. Further, the wheel control unit 5 acquires the current rotation angle of the wheel motor from the wheel motor 12. The actuator control unit 6 receives the target length from the crossing assistance operation generation unit 4 and controls the actuator 14 to have the target length.

Processing and operation inside the movement control unit 3 will be described.
In accordance with the movement command, the movement command unit 7 is a movement target locus to be followed by the inverted pendulum moving body 1. The target rotation angle θr, the target rotation angular velocity dθr of the motor 12, the target longitudinal tilt angle φr of the moving body 10, A direction inclination angle dφr is generated.

  The movement command may be determined in advance by a program, or may be determined by a human in real time through an interface connected to the movement command unit 7. Further, the target rotation angle θr of the drive wheel 13 is obtained by integrating the target rotation angular velocity dθr, and similarly, the target front-rear direction inclination angle φr is integrated with the target front-rear direction inclination angular velocity dφr.

  The target rotational angular velocity dθr can be given, for example, in a trapezoidal pattern, and the target longitudinal angular velocity may always be zero. The inversion control unit 8 receives from the movement command unit 7 from the movement target locus and the gyro 11 the front-rear direction tilt angle θ and the front-rear direction tilt angular velocity dθ of the moving body 10, and the wheel control unit 5 receives the wheel motor rotation angle θ and the rotation angular velocity dθ. And the inverted torque τi is calculated according to Equation 1.

  Here, K1, K2, K3, and K4 are inverted gains, and are determined by using various control theories such as LQR, machine learning, and the like. If the inverted torque τi is output from the wheel motor 12 and the inverted pendulum moving body 1 is on a flat and smooth road surface, the inverted pendulum moving body 1 is inverted.

  The processing of the crossing assistance operation generation unit 4 will be described with reference to the flowchart of FIG. 4 while focusing on only one wheel that may contact the step. The crossing assistance operation is executed at a constant cycle.

  FIG. 4 is a flowchart for explaining the processing of the travel stabilization apparatus according to the embodiment of the present invention.

  In S1, the crossing assist operation generation unit 4 receives the wheel motor rotation angular velocity dθ from the wheel control unit 5, the front and rear direction inclination angle φ and the front and rear direction inclination angular velocity dφ from the gyro 11, and dθr, φr, which are movement target loci from the movement command unit. Obtain dφr.

  In S2, the crossover assisting motion generation unit 4 obtains the difference between dθr and dθ and the difference between φr and dφr, and when both of the differences are equal to or larger than a preset value, the step A touches the step A shown in FIG. It is determined that If it is determined that it is in contact with the stepped portion A, the process proceeds to S3, and if it is determined that it is not in contact with the stepped portion A, the overpass assistance is terminated.

  In step S3, the crossing assistance operation generation unit 4 determines the actuator lifting amount Hu according to Equation 2. When the Hu minute actuator 14 is pulled up, the apparent step height from the drive wheel 13 is reduced, and the drive wheel 13 can get over the step portion A with less energy.

  Further, according to Equation 3, the overpass assist wheel torque τc is determined. Torque necessary for the inverted pendulum moving body 1 to get over the stepped portion A is supplemented to the wheel motor 12 by the overturning assist wheel torque τc.

  P1, P2, R1, and R2 in Equations 2 and 3 are scalar amounts for adjusting the actuator lifting amount Hu and the overriding assist wheel torque τc, and can be determined empirically by experiments.

  In S <b> 4, the overpass assist operation generation unit 4 outputs the actuator pull-up amount Hu to the actuator control unit 6 and the overpass assist wheel torque τc to the wheel control unit 5.

  In S <b> 5, the crossing assistance operation generation unit 4 acquires the front-rear direction tilt angular velocity dθ and the left-right direction tilt angle Ψ from the gyro 11.

  In S6, the crossing assistance operation generation unit 4 determines whether the forward / backward tilt angular velocity dθ is positive or negative. If dθ is positive, it is determined that stepping has been completed, and if it is negative, it is determined that stepping has been continued. If the step over has not been completed, the process returns to S2.

  In S7, the overriding assisting motion generating unit 4 subtracts a predetermined value from the actuator lifting amount Hu so as to gradually return the actuator lifting amount Hu to 0 while maintaining the horizontal tilt angle Ψ of the moving body 10 at 0. ,calculate. As a result, the inverted pendulum moving body 1 can be prevented from falling in the left-right direction. Further, the overpass assist wheel torque τc is set to zero.

  In S8, the overpass assist operation generation unit 4 outputs the actuator pull-up amount Hu to the wheel control unit 5 in the same manner as in S4, and outputs the overpass assist wheel torque τc.

  In S9, the overpass assistance operation generation unit 4 ends the overpass assistance if the actuator lifting amount Hu is 0, and returns to S7 if not.

  Thus, a series of processes for assisting overstepping of the stepped portion A is completed. However, as soon as it is completed, stepping over assisting processing may be always performed by starting the stepped portion overriding assistance again.

  As described above, FIG. 4 illustrates the step-over assistance operation focusing on only one wheel that may come into contact with the step, but both wheels may come into contact with the step. In that case, the above operations are performed independently on the left and right. Further, when the actuator controller 6 drives the actuator, the actuator is operated at an acceleration equal to or higher than the gravitational acceleration.

  As a result, even when both wheels climb over the step at the same time, the load applied to the drive wheel 13 is reduced, so that the step portion can be climbed with less wheel torque. Also, the lifting amounts of the left and right actuators of the right drive wheel 13 are set to Hur and Hul. At this time, the overriding assist motion generation unit 4 acquires from the gyro 11 when returning the left and right actuator lifting amounts Hur and Hul to 0. Using the possible horizontal tilt angle, the mobile body 10 is gradually decreased so that the horizontal tilt angle Ψ of the mobile body 10 becomes zero. As a result, the inverted pendulum moving body 1 can be prevented from falling in the left-right direction.

  As mentioned above, although one Example of this invention was described, this invention is not limited to such an Example, A various deformation | transformation is possible for a use purpose and the reason for mounting.

  For example, instead of Equation 2, Equation 4 may be used.

  In this case, since the deviation with respect to the longitudinal inclination angular velocity dφ of the moving body 10 is used as compared with Formula 2, the actuator lifting amount Hu becomes large at an early stage of the step contact. Therefore, the step can be overcome while the deviation of the front-rear direction inclination angle θ of the movable body 10 is kept small.

  Similarly, Formula 5 may be used instead of Formula 3.

  In this case, since the deviation with respect to the longitudinal inclination angular velocity dφ of the moving body 10 is used as compared with the mathematical formula 3, the overpass assist torque τc is increased at an early stage of the step contact. Therefore, it becomes possible to get over the step more quickly and the influence of the step of the moving speed of the mobile body 10 is reduced.

  P3 and R3 in Equations 4 and 5 are scalar amounts for adjusting the actuator pull-up amount Hu and the overpass assist wheel torque τc, and can be determined empirically by experiment.

  As described above, according to the present invention, when the inverted pendulum type moving body travels and steps over the step, the main body longitudinal angular velocity and wheel speed, which are the effects that appear on the inverted pendulum type moving body due to the step, are measured, and these are set values. By discriminating whether or not the above has changed, the level difference is detected by reliably detecting the level difference, driving the actuator on the wheel side that has changed beyond the set value, and changing the vertical position of the wheel. Since the torque required for getting over the step is reduced because the wheel is apparently smaller than the wheel, it is possible to provide an inverted and stabilized traveling device capable of realizing stable traveling.

  DESCRIPTION OF SYMBOLS 1 ... Moving body, 2 ... Movement mechanism, 3 ... Movement control part, 4 ... Passing assistance operation | movement production | generation part, 5 ... Wheel control part, 6 ... Actuator control part, 7 ..Moving command unit, 8... Inverted control unit, 10... Moving body main body, 11... Gyro, 12.

Claims (4)

Inverted pendulum type moving body comprising a pair of wheels suspended on a moving body, a drive mechanism for rotating the wheels, and a drive control unit for maintaining the inverted state of the mobile robot body by controlling the drive mechanism In
A wheel rotation speed measuring unit for measuring the rotation speed of the wheel;
A main body front-rear direction angular velocity measurement unit that measures a tilt angular velocity in the front-rear direction of the mobile body, and
A suspension actuator for moving the wheel in the vertical direction;
A suspension actuator driving section for driving the suspension actuator,
When the main body longitudinal angular velocity measured by the main body longitudinal angular velocity measurement unit and the left or right speed of the pair of wheels change to a set value or more, the suspension actuator on the wheel side that has changed to a set value or more is changed. An inverted pendulum type moving body that is driven to change the wheel up and down. The inverted pendulum type moving body according to claim 1,
A main body front-rear direction angle measuring unit that measures a tilt angular velocity in the front-rear direction of the mobile body, and
When the main body front-rear direction angle measured by the main body front-rear direction angle measurement unit and the left or right speed of the pair of wheels change to a set value or more, the suspension actuator on the wheel side that has changed to a set value or more An inverted pendulum type moving body that is driven to change the vertical position of the wheel.   The inverted pendulum type moving body according to claim 1 or 2, wherein a driving torque is added to a wheel on a side where a wheel position is moved upward in accordance with a moving amount of the wheel. An inverted pendulum type moving body comprising a drive mechanism. In the inverted pendulum type moving body according to claim 1 or 2,
An inverted pendulum type moving body, wherein a suspension actuator is driven so that the vertical positions of the pair of wheels are equal when a longitudinal inclination angle velocity or a longitudinal inclination angle of the movable body is equal to or less than a set value. .

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